500HP target turbo - GTX30 vs ?

**Thuppu** · 23 November 2010, 19:39

I just got a CT5658 BB turbo. I was promised with superb spool and 500+hp. Lets see when I got it fitted...

**button** · 23 November 2010, 21:28

Only HX35:

1,8bar boost

**mastermind** · 25 November 2010, 10:11

Thnx Guys

I beleive that the CT and precision Turbos flow better than off-the-shelf units, so will look at it.

There has not been much comment here on the GTX's so I presume its too new to really say.

The HX35 seems to have been ahead of the GT's but I think we need to wait and see if the GTX's prove better. Do these fit on the standard Manifold, i.e. KKK hot side?

Anyone else have experience with a turbo that spools like a GT3071 that will yeild 500+ HP?

**Billman** · 25 November 2010, 11:09

I just looked at some pictures and it seems that garretts idea of high flow turbo is to remove the secondary blades of the compressor impeller and actually make a billet aluminium turbine impeller :-p

What is the effect of secondary impellers??? Don't know for sure but i am guessing that since the turbine wheels doesn't have some (and turbine weels must flow well with much exhaust gas) i am thinking that they are there to provide enough flow at slow impeller speeds and that would mean that these
turbos will for sure be worse low down than their equivalent but it would make their surging issues better.

So to sum up i would say that they made the impeller design actually better by reducing weight (billet and no secondary blades) and going back by 50 years in impeller design.
What is your opinion?

Here some pictures for reference

Garrett GTX

Precision Billet

Holset Billet

Compturbo Billet (could not find a better picture)

**keithsw0** · 25 November 2010, 11:59

i have gone for precision 5557 and was also told that i will make 500 and spool as quick as 3071 fingers crossed

**Rocco** · 25 November 2010, 13:34

Originally posted by mastermind

Thnx Guys

I beleive that the CT and precision Turbos flow better than off-the-shelf units, so will look at it.

There has not been much comment here on the GTX's so I presume its too new to really say.

The HX35 seems to have been ahead of the GT's but I think we need to wait and see if the GTX's prove better. Do these fit on the standard Manifold, i.e. KKK hot side?

Anyone else have experience with a turbo that spools like a GT3071 that will yeild 500+ HP?

the GT3071 0.63ar at 2.0bar coul be??

**Billman** · 25 November 2010, 16:01

Originally posted by Rocco

the GT3071 0.63ar at 2.0bar coul be??

At 7500 and 2 bar its far outside the compressor efficiency map and with the 0.63 the back pressure would be too excessive.

**A80Avant** · 25 November 2010, 16:10

i believe so as well that spooling will not be too much affected unless there is a turbine downsize. so 0.63 would be too constricted on the high rev area. i have been tuning an rs2 with the 3071r turbo 0.63ar these days here in greece for 95octane fuel and sure, the amount of boost it can create from down low is very good as it starts very early but it also runs out fairly fast. so fairly ideal mid range turbo.

**mastermind** · 26 November 2010, 05:53

I dont have enough knowledge around the impeller influence to comment intelligently about the new design yet, but will do some further reading up.

The 3071 on my car atm holding 1.6bar to red line does 450HP, but with race fuel and everything else being perfect.

Maybe the new GTX 3071 will give over 500HP but the current 3071 wont reach it on the S2, maybe with some other major changes, but then will the 0.63 A/R cause excessive back pressure and high egts when chasing 500 with the new GTX 3071?

Precisons 5557 looks good. Do you know where I can get Comp Map for this turbo?

**Rocco** · 26 November 2010, 06:42

Originally posted by mastermind

I dont have enough knowledge around the impeller influence to comment intelligently about the new design yet, but will do some further reading up.

The 3071 on my car atm holding 1.6bar to red line does 450HP, but with race fuel and everything else being perfect.

Maybe the new GTX 3071 will give over 500HP but the current 3071 wont reach it on the S2, maybe with some other major changes, but then will the 0.63 A/R cause excessive back pressure and high egts when chasing 500 with the new GTX 3071?

Precisons 5557 looks good. Do you know where I can get Comp Map for this turbo?

a car of a friend of mine did 523hp with 683nm with GT3071 0.63ar .... with the oem exhaust sistem,without cats.and with Wagner front instake and BIG IC....

do you know if is it possible?? or there is something wrong and totally crazy?

**diesel des** · 26 November 2010, 07:21

Yea, the gt3071r will flow for 500hp. But I wouldn't run it like that for track work.

Turbos are always a compromise, and the one you have is amung the best for quick spool 450hp. Will 10% more power really be worth chasing, at the expenses of slightly more lag?

If so look at the new bw ceramic ones coming out, not the gtx garrett.

**mastermind** · 26 November 2010, 08:16

Originally posted by Rocco

a car of a friend of mine did 523hp with 683nm with GT3071 0.63ar .... with the oem exhaust sistem,without cats.and with Wagner front instake and BIG IC....

do you know if is it possible?? or there is something wrong and totally crazy?

I dont think its possible, but your friend may have other work done to the engine to increase the Volumetric Effiecency and I also tried to use higher boost (1.9Bar) and found egts going very high, timing pulling back but huge Nm on my car.

I am also installing the Wagner Short Intake with Intercooler and install my VEMS as well, so this may give me the 450HP consistantly, but is not enough for the hillclimb events I also use the car for.

**mastermind** · 26 November 2010, 08:23

Originally posted by diesel des

Yea, the gt3071r will flow for 500hp. But I wouldn't run it like that for track work.

Turbos are always a compromise, and the one you have is amung the best for quick spool 450hp. Will 10% more power really be worth chasing, at the expenses of slightly more lag?

If so look at the new bw ceramic ones coming out, not the gtx garrett.

You absolutely right. I have been thinking about this and if the miracle turbo is not available

(3071 spool with 3076 power) then maybe its worth looking at 550 HP. considering 7A cams (RS2 cams atm), and rev higher for 550HP.

But there are those that say the HX35 , the 5557 and as you mention the BWs may offer what I'm looking for. So I will have to look at the comp maps of these and try and go by the experience of others and then make a decision.

**A80Avant** · 26 November 2010, 18:23

comp maps are not available. you need to trust them.
no matter how much i tried before buying any other turbo than the 3071,the comp people are not giving out any info unfortunatelly

500HP target turbo - GTX30 vs ?

500HP target turbo - GTX30 vs ?

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